Hydroentangling or spunlacing is a technique introduced during the 1970'ies, see e g CA patent no. 841 938. The method involves forming a fiber web, which is either drylaid or wetlaid, after which the fibers are entangled by means of very fine water jets under high pressure. Several rows of water jets are directed against the fiber, web which is supported by a movable wire. The entangled fiber web is then dried. The fibers that are used in the material can be natural fibers, especially cellulosic pulp fibers, man-made staple fibers, which may be synthetic, e g polyester, polyamide, polyethylene, polypropylene, or regenerated staple fibers, eg viscose, rayon, lyocell or the like, and mixtures of pulp fibers and staple fibers. Spunlace materials can be produced in high quality to a reasonable cost and they possess a high absorption capacity. They can e g be used as wiping material for household or industrial use, as disposable materials in medical care and in hygiene purposes etc.
Through e g EP-B-0 333 211 and EP-B-0 333 228 it is known to hydroentangle a fibrous mixture in which one of the fiber components is continuous filaments in the form of meltblown fibers.
In WO 96/02701 there is disclosed hydroentangling of a foam formed fibrous web. The fibers included in the fibrous web can be pulp fibers and other natural fibers and man-made fibers.
During the hydroentanglement the fiber web is supported either by a wire or a perforated, cylindrical metal drum. An example of a hydroentanglement unit of this kind is disclosed in for example EP-A-0 223 614. However, supporting members in the form of wires of the type utilised in connection with paper production is the most frequently occurring type as for example is shown in EP-A-0 483 816. One disadvantage with using wires of this type is that the fiber web, during the hydroentanglement, is exerted to a strong action by the water jets and will penetrate into and get caught between the wire threads. It may then be difficult to separate the final product from the wire.
WO 01/88261 discloses the use of a moulded, close-meshed screen of thermoplastic material as supporting member during hydroentanglement of a fibrous web. The removal of the final product from such screen is simplified as compared to a wire.
When making a nonwoven material, especially a material that is intended to be used as a wiping material, there a many properties that are important, such as absorptive capacity, absorption speed, wet strength, softness, drapability, low linting, high cleaning ability etc. It is however difficult to combine all these properties in one and the same material. It is for example possible to make cloth like, soft, strong and low linting hydroentangled nonwoven material by using 100% synthetic fibers. However the absorption properties of such a material will be low. Materials containing a high amount of pulp fibers have a high absorptive capacity, but a poor wet strength and high linting. The wet strength and linting properties can be improved by the addition of chemicals, such as wet strength agents and binders.